36 research outputs found

    A kind of coordinated evolution measurement model for traffic network based on complexity degree

    Get PDF
    Coordinated evolution is a process with complexity, temporality, spatiality, and continuity. The existed methods cannot relevantly satisfy and measure the degree of coordinated evolution in real conditions. Aiming at solving the coordinated evolution problems for the urban traffic network, the information complexity must be evaluated, this paper uses the multi-dimensional connection number for compressing the factors of traffic network. Firstly, the basic characteristics of traffic network are analysed on the definition of traffic information complexity. The traffic network measurement model is established based on the information entropy, and the coordinated evolution process of the multi-layer urban traffic network is analysed for defining the ordered parameters of the traffic network. Then the coordinated measurement model for the multi-layer traffic network is constructed by the ordered parameters. In addition, we set up a coordinated evolution model according to the proposed estimation criteria of the ordered parameters and the theory of the multi-dimensional connection numbers. The case analysis shows that the order degree of Hangzhou traffic network is 0.7929, which approaches to 1 as while the comprehensive coordinated index of Hangzhou multi-layer traffic network is 0.3323, which clearly and intuitively gives a measurement value for the multi-layer urban traffic network. The result is also effectively verified the validity of the proposed models

    An Application of Hierarchical Structure Model for Trip Mode Choice Forecasting in China

    Get PDF
    Trip mode split is the result of interrelated and mutually independent factors, such as city scale, urban form, economic level, trip distance, and travel time. In order to analyze the formation of traffic structure, it is necessary to make a comprehensive study on the mechanism of these factors and obtain the basic causal relationship of them. Based on this, by using the hierarchical structure model in system engineering, this paper firstly clarifies the logical relationship of different factors. Then, the existing trip survey data of several cities is used to establish the mathematical relationship of various factors of the structure model. Finally, the mode choice forecasting method is proposed based on the structure model of influencing factors. The case study result of six cities shows small bias, indicating that the proposed method is of great practical value. Policy makers can use the results to discover the trip structure feature and grasp the direction of transportation development policy

    Modeling Pedestrian’s Conformity Violation Behavior: A Complex Network Based Approach

    Get PDF
    Pedestrian injuries and fatalities present a problem all over the world. Pedestrian conformity violation behaviors, which lead to many pedestrian crashes, are common phenomena at the signalized intersections in China. The concepts and metrics of complex networks are applied to analyze the structural characteristics and evolution rules of pedestrian network about the conformity violation crossings. First, a network of pedestrians crossing the street is established, and the network’s degree distributions are analyzed. Then, by using the basic idea of SI model, a spreading model of pedestrian illegal crossing behavior is proposed. Finally, through simulation analysis, pedestrian’s illegal crossing behavior trends are obtained in different network structures and different spreading rates. Some conclusions are drawn: as the waiting time increases, more pedestrians will join in the violation crossing once a pedestrian crosses on red firstly. And pedestrian’s conformity violation behavior will increase as the spreading rate increases

    A Study on Urban Road Traffic Safety Based on Matter Element Analysis

    Get PDF
    This paper examines a new evaluation of urban road traffic safety based on a matter element analysis, avoiding the difficulties found in other traffic safety evaluations. The issue of urban road traffic safety has been investigated through the matter element analysis theory. The chief aim of the present work is to investigate the features of urban road traffic safety. Emphasis was placed on the construction of a criterion function by which traffic safety achieved a hierarchical system of objectives to be evaluated. The matter element analysis theory was used to create the comprehensive appraisal model of urban road traffic safety. The technique was used to employ a newly developed and versatile matter element analysis algorithm. The matter element matrix solves the uncertainty and incompatibility of the evaluated factors used to assess urban road traffic safety. The application results showed the superiority of the evaluation model and a didactic example was included to illustrate the computational procedure

    RETRACTED: MRS and diffusion tensor image in mild traumatic brain injuries

    Get PDF
    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).The authors have plagiarized part of a paper that had already appeared in [Journal of Neurotrauma, 28: 1-11. http://dx.doi.org/10.1089/neu.2010.1578]. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

    Modeling the Commuting Travel Activities within Historic Districts in Chinese Cities

    Get PDF
    The primary objective of this study is to analyze the characteristics of commuting activities within the historical districts in cities of China. The impacts of various explanatory variables on commuters' travels are evaluated using the structural equation modeling (SEM) approach. The household survey was conducted in the historical districts in Yangzhou, China. Based on the data, various individual and household attributes were considered exogenous variables, while the subsistence activity characteristics, travel times, numbers of three typical home-based trip chains, trip chains, and travel mode were considered as the endogenous variables. Commuters in our study were classified into two main groups according to their working location, which were the commuters in the historic district and those out of the district. The modeling results show that several individual and household attributes of commuters in historic district have significant impacts on the characteristics of travel activities. Additionally, the characteristics of travel activities within the two groups are quite different, and the contributing factors related to commuting travels are different as well

    Modeling the Commuting Travel Activities within Historic Districts in Chinese Cities

    Get PDF
    The primary objective of this study is to analyze the characteristics of commuting activities within the historical districts in cities of China. The impacts of various explanatory variables on commuters’ travels are evaluated using the structural equation modeling (SEM) approach. The household survey was conducted in the historical districts in Yangzhou, China. Based on the data, various individual and household attributes were considered exogenous variables, while the subsistence activity characteristics, travel times, numbers of three typical home-based trip chains, trip chains, and travel mode were considered as the endogenous variables. Commuters in our study were classified into two main groups according to their working location, which were the commuters in the historic district and those out of the district. The modeling results show that several individual and household attributes of commuters in historic district have significant impacts on the characteristics of travel activities. Additionally, the characteristics of travel activities within the two groups are quite different, and the contributing factors related to commuting travels are different as well

    A KIND OF COORDINATED EVOLUTION MEASUREMENT MODEL FOR TRAFFIC NETWORK BASED ON COMPLEXITY DEGREE

    Full text link

    Braess Paradox in Optimal Multiperiod Resource-Constrained Restoration Scheduling Problem

    Full text link
    This study examines the Braess paradox in the context of the multiple-period restoration scheduling problem. A bilevel programming model is devised, where the upper-level problem is to determine the optimal sequence of recovery activities considering the limited resource constraint, while the low-level problem is the traffic assignment model that captures passengers’ responses to the changes in the transportation network capacity. Then, a novel genetic algorithm (GA) is developed to solve the proposed restoration scheduling problem. Our case study first shows that the optimal restoration schedule does not concur with the results obtained based on the link importance measurement, and the former can achieve a 4% total travel time reduction compared with the latter. Then, various numerical experiments are conducted to illustrate the occurrence and properties of the Braess paradox, which is that the network performance in some restoration periods can be better than that before the disruption or after a disrupted link is recovered. Moreover, it is revealed that with sufficient resources for multiple links to be repaired simultaneously, it is unnecessary to do so in the optimal rehabilitation schedule due to the existence of the Braess paradox. Finally, in terms of algorithmic performance, our proposed-GA outperforms the particle swarm optimisation algorithm and can reduce the computation time by up to 14%.</p
    corecore